From: Sebastian Reiter (
Date: Thu Jan 23 2020 - 10:03:06 CST

Hi John, Hi Robin,

thank you both very much for the advice. I got my hands on a machine
with a dedicated GPU now and the problem disappeared, so it was indeed
the display drivers.

Best regards


On 22.01.20 20:51, Robin Betz wrote:
> Hi Sebastian,
> I've had similar problems where the render window doesn't update in
> time for the snapshot to be captured.
> I believe premature optimization on the part of the display driver is
> to blame.
> The environment variable VMDMSECDELAYHACK sets the number of
> milliseconds between render calls. I have found values of 50-100 can
> fix this problem for me, although you will want to find the sweet spot
> between rendering at a reasonable rate and getting frame skipping.
> Hope this helps,
> Robin
> On Wed, Jan 22, 2020 at 11:33 AM Sebastian Reiter
> <
> <>> wrote:
> Hi,
> I am trying to make a movie of a protein with the ViewChangeRender
> and
> Movie Maker plugins and the snapshot render command. Particularly, I
> would like to slowly zoom into a specific site of a protein. However,
> snapshot sometimes seems to randomly zoom out a little from the
> current
> viewpoint. This causes the movie to stutter because the zooming
> motion
> is not continuous but interrupted by randomly offset frames.
> I know that it has something to do with snapshot, because a dry
> run with
> Movie Maker looks just fine. Also, the same thing happens, when I
> render
> a static scene with snapshot.
> Has anyone experienced this kind of issue before and knows a
> solution?
> If possible, I would like to stay with snapshot, because I am quite
> happy with the look and because more sophisticated rendering
> engines are
> too slow on my machine for a movie with a few hundred frames.
> I am using VMD 1.9.3 on a Ubuntu 18.04 64bit machine. The startup
> information of VMD says the following about the available graphics:
>      Info) Multithreading available, 4 CPUs detected.
>      Info)   CPU features: SSE2 AVX AVX2 FMA
>      Info) Free system memory: 3816MB (48%)
>      Info) No CUDA accelerator devices available.
>      Warning) Detected X11 'Composite' extension: if incorrect
> display
> occurs
>      Warning) try disabling this X server option.  Most OpenGL drivers
>      Warning) disable stereoscopic display when 'Composite' is
> enabled.
>      Info) OpenGL renderer: Mesa DRI Intel(R) HD Graphics 630
> (Kaby Lake
> GT2)
>      Info)   Features: STENCIL MSAA(4) MDE CVA MTX NPOT PP PS
>      Info)   Full GLSL rendering mode is available.
>      Info)   Textures: 2-D (16384x16384), 3-D (512x512x512),
> Multitexture (8)
> Thanks in advance and best regards
> Sebastian

Sebastian Reiter
Ludwig-Maximilians-Universität München
Department Chemie, AK de Vivie-Riedle
Butenandtstr. 11, Haus E, Raum E0.019
D-81377 München
Phone: +49 89 2180 77619